What the trial was testing
The Retatrutide Phase 2 enrolled 338 patients with obesity. The study was sponsored by Eli Lilly and Company and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was a mid-stage trial — researchers are testing whether the treatment actually works for the condition. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
~24% average body weight loss on the highest retatrutide dose at 48 weeks.
New England Journal of Medicine · 2023 · NCT04881760
These findings — that average body weight loss on highest-dose weekly retatrutide vs. placebo at 48 weeks — were published in the New England Journal of Medicine and represent the headline result of the study.
Researchers tracked outcomes across 338 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with obesity, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Retatrutide is NOT YET FDA-approved — it's in Phase 3 trials (the TRIUMPH program) and not commercially available. Phase 3 results are expected in 2026-2027; commercial availability would follow if results hold up. If you're interested in retatrutide trials, ask your doctor whether you might qualify, or search for active retatrutide trials on Stella or ClinicalTrials.gov.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open obesity trials
Resistance Training to Prevent Muscle Loss During Treatment With Tirzepatide
Incretin-based pharmacotherapies induce significant weight loss and represent a paradigm shift in obesity treatment. However, particularly fast weight loss may be accompanied by a significant loss of muscle mass, which is associated with a reduced metabolic rate at rest and during physical activity, increased insulin resistance, limited mobility, and potential long-term adverse effects. The aim of this clinical trial is to examine the effects of resistance training versus standard of care on contractile thigh muscle volume in patients receiving the dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists 'tirzepatide'.
Knee Injections for Obese Patients With Knee Arthritis
The purpose of this study is to assess obese patients with knee arthritis and determine the non-inferiority of a low dose steroid treatment vs. standard dose steroid treatment for two knee outcome measures: pain and function.